Moisture-vapor-permeable pressure-sensitive adhesive materials

ABSTRACT

This invention relates to a moisture-vapor-permeable pressure-sensitive adhesive material for use on animal skin and nails, e.g. a surgical drape, suture strip or sheet, adhesive dressing, bandage, plaster, strapping tape, decorative nail covering, or decorative cosmetic product. The adhesive material comprises a backing material and a pressure-sensitive adhesive on at least substantially the whole of the body adhering portion of at least one surface of said backing material, both said backing material and said adhesive being moisture-vapor-permeable and unaffected by water and at least one of said backing material and said adhesive comprising a synthetic polymer and .Iadd.both said backing material and said adhesive .Iaddend.being continuous and nonpermeable to liquid water, said adhesive material having a moisture vapor permeability of at least 300 g/sq. meter/24 hours/40° C./80 percent RH.

The present invention relates generally to adhesive materials for use onanimal bodies particularly human bodies. Examples of such materials are:adhesive bandages, plasters, dressings, surgical drapes, and decorativecosmetic products.

Where adhesive materials are to be used on parts of animal bodies e.g.,human bodies, it is desirable to have an adhesive material which ispermeable to water vapor, but which is not permeable to liquid water,micro-organisms and particles of dirt. These conditions are desirable inorder to provide the desired covering without causing maceration due toocclusion of water from transepidermal water loss from the body. Manymethods have been tried in order to obtain the results set out above.Methods at present in use involve the use of perforated, porous ormicroporous backing material having a porous or pattern spread adhesivelayer. Such constructions however do not provide a barrier to lowsurface tension aqueous solutions, e.g., washing-up liquid (which willalso allow bacteria to penetrate). Furthermore large holes in thematerial are not bacteriaproof and small holes are subject to beingblocked by grease etc. Special processes are also needed to produce suchmaterials.

According to the present invention there is provided amoisture-vapor-permeable pressure-sensitive adhesive material for use onanimal skin and nails, comprising a backing material having apressure-sensitive adhesive on at least substantially the whole of thebody-adhering portion of at least one surface of said backing material,both said backing material and said adhesive being moisture vaporpermeable and unaffected by water and at least one of said backingmaterial and said adhesive comprising a synthetic polymer and beingcontinuous and nonpermeable to liquid water, said adhesive materialhaving a moisture vapor permeability of at least 300 g./sq. meter/24hours/40° C./80 percent relative humidity (R.H.).

For the synthetic polymer used to form the continuous backing materialand/or the continuous adhesive to have the properties desired it shouldnot be highly crystalline, should not have a high proportion of hydrogenbonding and should include hydrophilic groups.

Evidences from various sources indicate that the average body loss ofwater through the skin excluding visible sweat is in the region of 250g./sq. meter/24 hours. Areas such as the palm of the hand and soles ofthe feet have a high water loss in the region of 500 g./sq. meter/24hours.

It follows that a permeability of at least 300 g./sq. meter/24 hours/40°C./80 percent R.H. is required for most areas but a figure of 500 ispreferred especially for wound dressings and surgical drapes.

The adhesive may be applied as an allover spread (continuous ordiscontinous) to one surface of the backing material or the adhesive maybe applied to body-adhering portions only to form for example a windowdressing, i.e., one in which the wound-covering area of the backingmaterial is not coated with adhesive.

It is clear that either the backing material or the adhesive, or both,may be continuous and nonpermeable to liquid water. All sucharrangements have a number of common advantages, for example themoisture vapor permeability feature allows the skin etc., to breathethereby preventing maceration and the impermeability to liquid waterfeature prevents ingress of water and egress of wound exudate where thematerial is used on a wound. The feature that both the adhesive and thebacking material are unaffected by water allows the dressing to beimmersed in water without adverse effect. Each of the three differentembodiments of the invention, however, has its own particular advantagesand the arrangement used for any particular purpose should be selectedbearing in mind these advantages. For example, in embodiments where onlythe backing layer is continuous and impermeable to water, dirt and waterare prevented from passing through the backing layer to the adhesivewhich may then allow the water and dirt to reach the body. Thearrangement where only the adhesive is impermeable to water will preventwound exudate from passing through the adhesive. The arrangement whereboth the adhesive and the backing material are continuous andimpermeable to water is particularly preferred since this has theadvantages given above for the arrangement where only one of the backingmaterial and adhesive is continuous. Furthermore the manufacture of thisembodiment is simplified since each of the layers may be produced in acontinuous manner. Also the possibility of pinholes in the backing layerand the adhesive coinciding is less when two continuous layers are usedsince any such pinholes present are accidental. Furthermorestrike-through of adhesive through the backing layer is prevented.

The expression "continuous" as used throughout the presentspecification, including the claims, is intended to mean that thematerial is such that it contains no discontinuities which are visible,either by the naked eye or under an optical microscope, and are suchthat water vapor passes through such materials by inter moleculardiffusion. The polymer may be visualized as a tangled mass of polymerchains with approximately molecular sized holes between them. At normaltemperatures there is considerable segmental mobility and the holes arecontinually forming and disappearing as a result of thermal motion.Diffusion of a penetrant takes place as a succession of "jumps" fromhole to hole.

The diffusion of a gas or vapor through such a continuous material doesnot depend on the fluid properties of the gas or vapor but on thestructures of the gas or vapor and the continuous material and chemicalaffinity of one for the other.

In the specification, including the claims the expression "unaffected bywater" when used to describe the backing material and/or the adhesive isintended to mean that the backing material and/or adhesive does not oncontact with water lose those properties which would effect itsperformance as a backing or adhesive, e.g., (a) the adhesive does notlose adhesion or cohesion due to solution and does not swell to causethe dressing etc., to come off and, (b) the backing does not lose itstensile strength, disintegrate or become tacky.

Where reference is made to moisture vapor permeability it is intendedthat such measurements are carried out by the Payne cup method, carriedout as follows.

Ten ml. of distilled water are added to the cup. A 11/4inch diametersample of the material to be tested is clamped above the opening fromthe cup. Where an adhesive is being tested this should first be coatedonto a highly permeable backing for support. The arrangement is thenplaced in an air-circulating oven at temperatures of 40° C. and relativehumidity of 20 percent for 24 hours. There is therefore a differencebetween the relative humidity inside the cup and the relative humidityoutside the cup. The loss of water from the cup is found by weighing.The moisture vapor permeability is expressed as g./sq. meter/24hours/40° C./80 percent R. H. for the particular material.

The expression "pressure-sensitive adhesive" as used throughout thespecification, including the claims, is intended to mean an adhesivewhich is inherently tacky, viscoelastic and cohesive in its normal drystate. Clearly the adhesive used must be capable of adhering to thatpart of the body to which it is to be attached.

Where reference is made to adhesive being on "substantially the whole ofthe body-adhering portion of the backing material" it is not intended toexclude the possibility of the adhesive being discontinuous to an extentsufficient to provide the body-adhering portion with an average m.v.p.of at least 300.

The adhesive materials of the invention should be nontoxic, nonirritant,conformable and should maintain their properties over a range ofconditions and time. The backing material should be nontacky underconditions of use.

The adhesive materials may be used on any part of the human body, e.g.,for surgical, dermatological or cosmetic use. Some examples of specificuses of the adhesive material of the invention are as surgical drapes,suture strips and sheets, adhesive dressings, bandages, plasters,decorative nail coverings, solid eye liners, wrinkle producers (fortheatrical make up) etc.

The adhesive materials of the present invention may result in thefollowing advantages:

1. Prevent occlusion of moisture under the structure which can injurethe skin or nail.

2. Allow oxygen through from the outside. This is important to healingof wounds.

3. Prevent ingress of liquid water.

4. Prevent ingress of bacteria.

5. Are unaffected by water.

Some degree of isotropic elasticity in the backing material is desirablefor some applications. This is however not essential, and nonelasticbacking materials such as cretane may be used, if desired.

Continuous adhesives may be formed from polymers containing hydrophilicgroups such as hydroxyl, carboxyl, amine, amide, ether and alkoxyproviding that the adhesives are not soluble or highly swollen in water.

However, water-soluble or water-swellable polymers can be added topressure sensitive formulations provided they are compatible and do notcause the adhesives to be affected by water (for example apolyvinylmethyl ether may be added to a polyvinylethyl ether adhesive ora hydroxy propyl acrylate homopolymer may be added to a compatiblepressure-sensitve adhesive); other water-soluble or water-swellablepolymers which may be used are cellulose esters, polyvinyl alcohol andother hydrophilic materials. Similarly water-soluble monomers can beused in water-insensitive copolymers.

Examples of materials which may be used as the continuous adhesive areblends of vinyl ether or acrylic polymers, with or without the additionof tackifying resins. Hydroxy acrylate polymers may also be used insuitable formulations.

Preferred water-impermeable adhesives are polyvinyl ethyl ethers andcertain acrylate ester copolymers containing hydrophilic groups.

The polyvinyl ethyl adhesives may be obtained in a wide range ofviscosities. A particularly preferred polyvinly ethyl ether adhesive isa composition comprising the following ingredients:

    ______________________________________                                                         Amount                                                                        (Parts by weight except                                      Ingredient.      where stated).                                               ______________________________________                                        Bakelite EDBC (see below)                                                                      50                                                           Bakelite EHBM (see below)                                                                      100    (solution as received)                                Kelrez ZR 142 (see below)                                                                      25                                                           Antioxidant (Nonex WSL)                                                                        3                                                            60-80  petroleum ether                                                                         300    mls.                                                  ______________________________________                                    

Polyhydroxy propyl acrylate is a tacky rubbery polymer which may beconverted into a pressure-sensitive adhesive composition bycopolymerization. The homopolymers generally cross-link duringpolymerization but linear polymers may be obtained by solventpolymerization provided the concentration of monomer is low.

Suitable acrylate ester copolymer adhesives found so far are Acronal KR2156 (B.A.S.F) and D.260 (Shawinigan). Blends of acrylic and polyvinylethers found to be useful as adhesives include (a) a mixture of 50 partsby weight Acronal 40D (B.A.S.F.) and 50 parts by weight Lutanol M 40,and (b) a mixture of 100 parts by weight Gantrez M 574, 50 parts byweight Gelva D 260 and 25 parts by weight of Kelrez ZR 142.

Where a continuous adhesive is used, the adhesive may be applied to thebacking material in solution, aqueous dispersion, as a hot melt, or by atransfer process, using known techniques, e.g., knife, roller-coating orcurtain coating methods. In practice the transfer process has been foundto be particularly convenient. The adhesive solution is spread onrelease-coated paper, and almost dried before contacting the backingmaterial under sufficient pressure to ensure good contact. The releasepaper is then removed. Other methods may however prove to be morepracticable in commercial use.

Any suitable adhesive may be used where the adhesive is to bediscontinuous. The discontinuities should not be too big, i.e., theadhesive layer should contact the skin etc., over most of the area ofthe dressing.

The adhesive can be made porous by foaming, leaching out solublefillers, pattern spreading, e.g., as shown in British Pat. No. 819,635spraying or selective layer perforating.

Where the backing material is continuous any material which iscontinuous and is water-vapor-permeable but liquid water impermeable maybe used, although for many uses other properties, e.g., conformabilityand oxygen permeability, are desirable.

Useful materials include cast films of thermoplastic polyurethane andother polymers containing nonbound (free to interact with water)hydrophilic groups e.g., --OH, --COOH, --NH₂, --NH, alkoxy and etheretc.,) provided they are unaffected by water, as defined above.

Preferred continuous backing materials are:

I. A copolymer obtainable by copolymerizing an hydroxy alkyl acrylate ormethacrylate with an alkoxy alkyl acrylate or methacrylate andoptionally with a minor amount of a further monomer.

Copolymers of this type are described in G.B. application No. 50,044/68.

If desired more than one hydroxyalkyl acrylate or methacrylate and/ormore than one alkoxy alkyl acrylate or methacrylate may be used asmonomers.

Preferably the minor amount of further monomer is no more than 10percent by volume based on the total volume of monomers.

Preferred further monomers are acrylic acid methacrylic acid acrylamide,mono- and di- acrylates of glycols and poly glycols, (e.g. glycerol andpolyalkylene glycols), mono- and di-methacrylates of glycols andpolyglycols (e.g., glycerol and polyalkylene glycols, glycidyl acrylatesand glycidyl methacrylates).

The further monomer or monomers may be present as an impurity in themajor constituents of the reaction mixture or may be specifically added,e.g., to provide for cross-linking.

The preferred hydroxy alkyl acrylates and methacrylates are hydroxyethyl methacrylates (HEMA), hydroxyl propyl acrylate (HPA) and hydroxypropyl methacrylate (HPMA).

Preferred alkoxy alkyl acrylates and methacrylates are ethoxy ethylmethacrylate (EEMA) and methoxy ethyl methacrylate (MEMA).

The properties of these copolymers will vary depending on theproportions of the various ingredients used to make up the copolymer. Ingeneral copolymers with a high proportion of alkoxy alkyl acrylate ormethacrylate (e.g., EEMA) give flexible, high moisture-vapor-permeablenon-water-swellable films at 20° C. whereas a high proportion of ahydroxy alkyl methacrylate (e.g., HEMA) will give highmoisture-vapor-permeable brittle, water-swellable films (properties at20° C.). For example, a copolymer made up from 80 percent by volume EEMAand 20 percent by volume (HEMA is flexible and is not affected by water,whereas a copolymer made up from 50 percent by volume EEMA and 50percent by volume HEMA is brittle and is swollen by water.

Copolymers including more than 30 percent hydroxyl ethyl acrylate ormethacrylate are affected by water and are thus not included asmaterials which can be used as backing materials in the presentinvention.

These copolymers may be prepared by copolymerizing an hydroxyalkylacrylate or methacrylate with an alkoxy alkyl acrylate or methacrylateand optionally with a minor amount of a further monomer. A free radialinitiator, for example, tertiary butyl peroctoate may be used. Thereaction may be performed in a solvent such as ethyl acetate, industrialmethylated spirits, ethanol, methanol, dimethyl formamide. The reactionis performed in an inert atmosphere under reflux for 8 hours. Thecopolymer may be precipitated by pouring into a nonsolvent such aspetroleum ether.

Alternatively, the above reaction may be taken to near completion byrefluxing, e.g., for 24 hours, to give a solution of the copolymer.Films may be formed from the solution of the copolymer by casting asolution of the copolymer onto a smooth surface, for examplerelease-coated silicone paper or cast polypropylene, drying andstripping the film off the smooth surface. To improve strengthcharacteristics the copolymers may be self-cross-linked by heating ormay be cross-linked by the addition of a cross-linking agent or acatalyst. A copolymer of 80 percent by volume EEMA and 20 percent byvolume HEMA may be partially self-cross-linked by heating at 120° C. for11/2 hours or longer in air atmosphere.

II. Homopolymers of alkoxy alkyl acrylates or methacrylates (linear orcross-linked) or from copolymers of one or more (preferably one) alkoxyalkyl acrylate or methacrylate with one or more (preferably one) alkylacrylate or methacrylate.

The moisture vapor permeability is reduced as the proportion of alkylacrylate or methacrylate is increased. Care should therefore be taken toensure that, in the final product, the moisture vapor permeability is atleast 300 by careful selection of the proporation of alkyl acrylate ormethacrylate, the thickness of the backing material and the nature andthickness of the adhesive.

Preferred monomers are ethoxy ethyl methacrylate (EEMA); methoxy ethylmethacrylate (MEMA); methyl methacrylate (MMA).

III. A copolymer obtainable by reacting an alkoxy alkyl acrylate ormethacrylate with a different alkoxy alkyl acrylate or methacrylate.Copolymers of this type are described in our GB application No.60,754/68. Although it is preferred that no monomers other than alkoxyalkyl acrylates or methacrylates or polymers formed therefrom arepresent in the reaction mixture, up to 10 percent of further monomers(see list above under I) may be present.

What reference is made to no monomers other than alkoxy alkyl acrylatesor methacrylates or polymers being present, it is to be understood thatthe reaction mixture may include very small amounts of the free acids asimpurities.

These copolymers may be produced by copolymerizing in an inertatmosphere an alkoxy alkyl acrylate or methacrylate with a differentalkoxy alkyl acrylate or methacrylate.

The reaction may be performed in the presence of a free-radicalinitiator, for example, tertiary butyl peroctoate.

The reaction may be performed in the absence of a solvent or in thepresence of a solvent, e.g., ethyl acetate, toluene, methanol ordimethyl formamide.

The copolymer may be precipitated by pouring into a nonsolvent such aspetroleum ether. Alternatively the reaction may copolymer. Films may beformed from a solution of the copolymer by casting completion by heatingdrying for a suitable length of time e.g., for 24 hours, to give asolution of the copolymer by casting the solution onto a smooth surface,for example, release-coated silicone paper or cast polypropylene, dryingand stripping the film from the smooth surface. The properties of thefilms and coatings of the copolymer of the invention depend on the typeand proportion of the monomers. For example, copolymers of ethoxy ethylmethacrylate (EEMA) and methoxy ethyl methacrylate (MEMA) and containinga high proportion of MEMA will tend to be stiff and brittle attemperatures in the region of 5° C. whereas similar copolymerscontaining a large proportion of EEMA will be flexible.

IV. Thermoplastic polyurethane films. Suitable films can be made byextrusion or preferably by solvent casting. Suitable materials, andtheir production are described in U.S. Pat. No. 2,871,218. Estane 5701and 5702 (B. F. Goodrich Co.) have been found to be particularlysatisfactory. Estane 5702 has been found to be the most useful of thesematerials.

This material is best cast as a tetrahydrofuran or acetone solution.

Properties of a 1-mil thick film of Estane 5702 are:

MVP 1,620 g.s.m./24 hr.

O₂ permeability 4,880 cc./m.² /Atmos./24 hr.

Tensile strength (p.s.i.) 5,300

Elongation 730 percent

Modulus at 300 percent extension (p.s.i.) <500

Hardness (Durometer A) 70

Low-temperature brittleness point (°F.) <-100

Where the backing material is not continuous any material having highmoisture vapor permeability may be used provided it is not affected bywater. In addition it is desirable for such backing material to be suchthat it acts as a screen for larger particles of solid materials such asdirt.

Examples of materials which may be used to form noncontinuous backingmaterial are microporous films of plasticized polyvinyl chloride(process for making such microporous film of p.v.c. is described in U.K.specification No. 884,232), and certain nonwoven and woven and knittedporous fabrics. Fabrics which may be used as the backing materialinclude nonwoven fabrics based on cellulose or synthetic polymer fiberswhich may be crimped and/or laid down in such a manner as to give anelastic fabric. A preferred type of fabric having the desirableproperties of omnidirectional stretch combined with high porosity andhigh strength even when wet, is that type of fabric based on extrudedcomposite synthetic fibers sold under the trade mark "Heterofil" byImperial Chemical Industries Limited.

Several of the spun-bonded polyester fabrics marketed as "Reemay"fabrics by DuPont and similar fabrics by Bondina Ltd. are similarlysuitable.

In some cases the adhesive may be applied directly to the backingmaterials. In other cases however a water-vapor-permeable tie coatingcontinuous or discontinuous may be needed to obtain adequate keyingbetween the adhesive and the backing material. For example acrylic andplasticized PVC films may be coated with some adhesives directly,without need for a primer coat, e.g., where the adhesive used is apolyvinyl ethyl ether a tie coating is not usually required. Howeverwhen using a backing material which includes Nylon a primer coat isrequired in order to obtain adequate keying between the adhesive andbacking material when wet. A suitable primer has been found to be abutadiene/vinyl-pyridine latex solid under the trade name "Gentac."

In some instances, when using a noncontinuous backing material theexposed surface of the backing material has been found to "fluff up"badly, as well as becoming soiled. Also there is a tendency for theadhesive to strike through the backing material, adding to the soilingproblem. This may be overcome by applying a thin coat of a flexible andextensible material on the exposed surface of the backing material. Inaddition to consolidating the surface, this coating could also providerelease properties useful when the product is used in a roll form, e.g.,for bandaging and strapping. Suitable material which may be used areconventional release coats such as polystearyl methacrylate.

Where the material is to be used as a surgical dressing, a pad may beattached to the adhesive-coated surface of the material.

The dressing pad when used is of conventional type and may, if desired,be made in situ by flocking vertically orientated fibers onto theadhesive surface.

Preferably a protector is provided to cover the adhesive which protectormay be removed from the material immediately prior to use.

The protector, when used, may be a smooth-release-coated paper, e.g., asilicone-release-coated paper, but other thin suitable films inert tothe adhesive may be employed.

The continuous portion of the material of the invention preferably has ahigh oxygen permeability especially where the material of the inventionis to be used as a wound dressing.

Where the adhesive material of the invention is being stored in such amanner that the adhesive can come into contact with the backingmaterial, e.g., if stored in the form of a reel, precautions must betaken to ensure the adhesive does not strongly adhere to the backingmaterial. For example, the backing material may be provided with arelease coating or a protector may be applied over the adhesive surface.This release coating may also serve to reduce soiling of the film inuse.

If desired the backing film or adhesive layer or both may be given apattern of thinner areas, e.g., by embossing, to enhance the vapor andgas permeability of the layers.

One of the preferred uses of the present invention is in decorativecosmetic products, e.g., nail covers, eye liners, beauty spots, stageeffects, e.g., wrinkle producers (attach to skin in stretched state).

the preferred backing films for use in nail covers are copolymers ofEEMA/HEMA (provided the amount of HEMA does not exceed 30 percent;EEMA/HPMA: MEMA/EEMA: copolymers of MEMA with other monomers e.g.,MEMA/HEMA; EEMA/MMA and homopolymers of MEMA. Particularly preferred are80/20 (volume percent) and 75/25 (volume percent) copolymers ofEEMA/HEMA: 90/10 (volume percent) and 80/20 (volume percent) copolymersof EEMA and MMA; and 80/20 (volume percent) copolymer of EEMA/HPMA;50/50, 60/40 and 70/30 MEMA/EEMA copolymers; 90/10 (volume percent) and80/20 (volume percent) copolymers of MEMA/HEMA and cross-linked versionsof these polymers. The film thickness is preferably from 1 to 3 mils.

The preferred adhesives for use in connection with the nail coves arepolyvinyl ethyl ether based adhesives, continuous film adhesives andfoamed porous adhesives. The adhesive is preferably applied in an amountof from 5 to 75 grams per square meter. Nail covers are preferablyglossy although they can have a matt finish. The films and/or adhesivemay be pigmented or dyed. The films may having printing on them.

The nail covers are conveniently made up as a kit of two sets of sixindividual nail covers mounted in a range of sizes on astiff-release-coated card.

The nail covers are removed from the nails by peeling or wiping with aspecial solvent. The material state to be preferred for nail covers arealso preferred for other decorative cosmetic products.

Another particularly preferred use of the present invention is informing adhesive medical and surgical dressings including first aiddressings and ward dressings.

The absorbent pad is generally placed centrally on the adhesive face ofthe material and the whole is preferably covered by a film or releasecoated paper protector. If desired, the dressings may be placed in asterile pack, e.g., one sterilized by ethylene oxide or by irradiation.

The preferred backing films and adhesives include those given in respectof the nail covers.

Other preferred backing materials are continuous thermoplasticpolyurethane films, e.g., the Estanes (B. F. Goodrich) particularlyEstane 5702 and 5701, and elastic fabrics coated with such materials orwith poly EEMA. Preferred discontinuous backing materials aremicroporous p.v.c., spun-bonded nonwoven fabrics, elastic woven fabricsand knitted fabrics.

Another preferred use of the present invention is in surgical drapes.These are large flexible sheets which are provided with a continuouslayer of adhesive on at least a part only of one surface.

Where only a part of one surface is coated, the adhesive-coated area maybe varied with the design of the drape and a film or release-coatedprotector is generally applied to the adhesive-coated area. Thisprotector is removed when it is desired to use the drape. Generally twouncoated margins are provided to enable the protector to be easilyremoved. Alternatively, the coated margins may be covered by areleasable protector strip. The drapes may be packaged as a roll in asterile pack and the shape of the drape may be varied to suit particularparts of the body.

Preferred materials, including both the backing material and theadhesive, are the same as those given for the nail covers. Anotherpreferred backing material is a polyurethane film.

If desired, a bacteriostat may be incorporated into the surgical drapeto prevent growth of infectious bacteria on its surface.

If desired, part of the surgical drape may be reinforced, for examplethe backing film may be reinforced with a light-weight spun-bondednonwoven fabric to prevent the film tearing or splitting, if particularstrength is required.

The surgical drapes of the present invention have a number of advantagesas set out below:

1. Moisture vapor and oxygen permeable, waterproof and bacteria proof.

2. They may be left in position on the body for long periods which ifconsidered desirable, enables

a. the drape to be adhered over the proposed area of operation and theincision line marked on the drape during the preoperative period.

b. the incision to be made accurately through the drape, the drapeprevents wound infection from the surrounding area and the cut edgesreinforce the wound edges.

c. the incision to be closed by surface suture strips and, if necessary,covered by an adhesive dressing (e.g., ward dressing) adhering to thesurface of the drape and the whole assembly to be left in contact withthe body surface until the incision is healed.

It may be convenient for the drape to be transparent to enable the woundto be observed during healing.

The drapes preferably have a matt surface to prevent light reflectionespecially for use in an operating theater.

Surgical drapes must be highly conformable to skin otherwise after anincision has been made the retraction of the skin from the incisionwould cause the drape to lift and allow blood etc., to pass between thedrape and the skin. The backing material is preferably antistatic.

Another use of the present invention is in suture strips. At presentwounds either caused by accident or caused during surgical treatment aregenerally closed by stitching. The present invention, however, providessmall flexible strips which may be used to prevent a wound from openingup.

The strips should have sufficient rigidity and cohesive properties toachieve the desired result. The suture strips may be mounted on arelease-coated paper or film strip and packaged in a sterile pack, suchas a film or coated paper peel pack. The size and shape of the suturestrips may, of course, be varied as desired. The following three formshave, however, been found to be of particular use.

1. Thin strips, e.g., one-eighth of an inch×3 inch mounted in multiplesof 5 or 10 on release-coated rectangular strip.

2. Rectangular strips, e.g., one-fourth of an inch×2 inch with a centralabsorbent pad, nonadherent strip or a central reinforced area eithermounted in groups on a release-coated sheet or individually wrapped witha protective facing.

3. A "butterfly" shape, i.e., wide ends and narrow waist either mountedin groups on a release-coated sheet or individually wrapped with aprotective facing.

Preferred backing materials for use in the production of the suturestrips are the same as those given for the surgical dressings.

Preferred adhesives are polyvinyl ethyl ethers.

The suture strips may be wholly or partially reinforced with woven ornonwoven fabrics, for example spun-bonded fabrics such a Reemay (as soldby E. I. Dupont de Nemours) I.C.I.). fabrics formed from Heterofilfibers (as marketed by I.C.I.). A fabric reinforcement may be present inany layer of the suture strip, for example on the uncoated film surface.

The suture strips preferably have a small amount of elasticity to aidclosure of the wound. The strip is adhered to one side of the wound andis then held under tension while adhering to the other side of thewound.

The suture strips of the present invention have a number of advantagesas set out below.

1. The moisture vapor and gas permeability properties enable the stripsto be left in position for as long as 10 days without irritation andtrauma of the skin.

2. Waterproof properties prevent removal by external water or woundexudate.

3. The strips may be used for tissue grafts.

Another particular preferred use of the present invention is in elasticadhesive bandages and strapping tapes. These products comprise lengthsof the adhesive material described above and are generally in the formof reels. Since in some cases the adhesive will tend to adhere stronglyto the backing material when in reel form, it is desirable to use eithera release coat on the backing material or a protector on the adhesive.

The preferred continuous backing materials for strapping tapes are filmsof copolymers of EEMA/HEMA; EEMA/HPMA; EEMA/MMA MEMA/HEMA and EEMA/MEMAreinforced by woven or nonwoven fabrics. Preferred discontinuous backingmaterials for strapping tapes include woven and nonwoven fabrics withgood tensile strength.

The preferred backing materials for elastic bandages are knittedfabrics, e.g., knitted nylon, fabrics containing elastic threads, andhigh-twist cotton fabrics (elastic bandages) which may be coated withpoly-ethoxy ethyl methacrylate or thermoplastic polyurethane.

The preferred adhesive is polyvinyl ethyl ether.

The backing material for the elastic bandages preferably has a highdegree of stretch with good recovery properties whereas when used as astrapping tape the backing material is preferably more rigid, althoughit must still be flexible.

The main advantage with the bandages and strapping tapes is that theyare waterproof yet moisture vapor and gas permeable thus allowing thebandages or tapes to be adhered to the skin without irritation or traumadeveloping.

IN THE DRAWINGS

FIG. 1 is a graph showing, for one form of the adhesive material of theinvention, the relationship between moisture vapor permeability andthickness of backing material and amount of adhesive;

FIG. 2 is a diagrammatic sketch of an adhesive material in accordancewith the invention,

FIG. 3 is a diagrammatic sketch of a nail cover in accordance with theinvention,

FIG. 4 is a diagrammatic sketch of a number of nail covers mounted on asingle mounting,

FIG. 5 is a diagrammatic sketch of an adhesive medical or surgicaldressing in accordance with the invention,

FIG. 6 is a diagrammatic sketch of a suture strip in accordance with theinvention,

FIG. 7 is a diagrammatic sketch of a surgical drape in accordance withthe invention.

FIG. 1 is described in connection with Example 16.

In FIG. 2 an adhesive material is shown comprising a backing material 2,which may or may not be continuous and an adhesive 4 which may becontinuous or discontinuous on one surface of the backing material 2. Atleast one of the backing material and the adhesive is continuous. Asshown in FIG. 2 a protector, removable for use is provided for theadhesive although this is optional. By making the backing from anelastic material, an elastic bandage or tape may be obtained. Theadhesive material of FIG. 2 is in the form of an adhesive tape.

In FIG. 3 there is shown a nail cover 14 of the invention. The nailcover includes a backing material, an adhesive and a protector 6 as inthe material of FIG. 1 and has a cuticle-contacting curved portion 8 anda body portion 10. The protector is removed and the cover applied to thenail. The material used should be such that the cover will conform tothe curvature of the nail. When the cover has been applied to the nailthe squared end of the portion 10 is trained to the desired length andshape. If desired the nail covers may be produced as a set (see FIG. 4)mounted on a common mounting the mounting 12 replaces the protector. Theindividual nail covers 14 on the mounting 12 are of cuticle-contactingportions of the covers one of varying radii and six covers are providedfor each hand to enable selection of the current radiuscuticle-contacting portion to be selected. The covers are removed fromthe mounting for use. A strip of a protective material 16 which issubsequently removed may be provided on each nail cover 14 to enable itto be easily removed from the mounting 12 and for ease of handling.

FIG. 5 shows an adhesive medical or surgical dressing of the invention.This comprises a backing material 2 and an adhesive 4 as in thearrangement of FIG. 1. A dressing pad 18 is situated roughly centrallyof the dressing on the adhesive side. A protector is provided to coverthe pad and adhesive. The protector is removed when the dressing isrequired for use.

FIG. 6 shows a suture strip of the invention. This comprises a narrowstrip of pressure-sensitive adhesive material including a backingmaterial 2 and an adhesive 4. A fabric reinforcement 20 is provided onthe uncoated side of the backing material. A protector 6 covers theadhesive side and is removed when the strip is to be used to prevent awound from opening up.

FIG. 7 shows a surgical drape of the invention comprising a backingmaterial 2 and an adhesive 4. The incision line is marked on the drapeas at 22. A removable protector 6 is provided by adhesives to facilitateremoval of the protector 6.

Material similar to those shown in FIGS. 2 to 7 may be used for variousother purposes. For example by using different shaped adhesive materialscomprising a backing and an adhesive other decorative cosmetic productssuch as beauty spots and eye liners may be formed. Also by using anelastic backing material a wrinkle producer for stage effect may beobtained. The material is stretched adhered to the skin and allowed tocontract causing a wrinkle effect.

The invention will now be described with reference to the followingexamples. In these examples where reference is made to moisture vaporpermeabilities the units are g./sq. meter/24 hrs./40° C./80 percent RH.

EXAMPLE 1

One surface of a backing material in the form of a lightweight fabric(weight 1 oz./sq.yd) formed from "Heterofil" fibers based on Nylon wasgiven a primer coat of "Gentac" and adhesive composition A (describedbelow) was then applied to the primer coated surface of the fabric in anamount of 75 g./sq. meter. The moisture vapor permeability of theadhesive material so produced was 500.

The adhesive coated material was made into first aid dressings butcutting to an appropriate size and applying a pad to part of theadhesive surface. The dressing gave satisfactory results and did notproduce skin maceration due to having too low a moisture vaporpermeability.

EXAMPLE 2

One surface of a backing material in the form of a lightweight fabric(weight 1 oz./sq.yd.) formed from Heterofil fibers based on Nylon wasgiven a primer coat of "Gentac" and adhesive composition B (describedbelow) was then applied to the primer-coated surface of the fabric in anamount of 70 g./sq. meter. The moisture vapor permeability of theadhesive material so produced was 835.

The adhesive-coated material was made into first aid dressings bycutting to an appropriate size and applying a pad to part of theadhesive surface. The dressing gave satisfactory results and did notproduce skin maceration due to having too low a moisture vaporpermeability.

EXAMPLE 3

An adhesive composition was prepared by dissolving a copolymer(Shawinigan D 260) of acrylic esters in a solvent system consisting oftoluene/Hexane/ethyl acetate. This adhesive was knife-coated on to amicroporous poly vinyl chloride foil having a moisture vaporpermeability of 4,500. Dry coating weight was 50 g./sq.m. Dressings madefrom this showed a moisture vapor permeability of 550 and adhered wellto skin.

No skin maceration developed in user trials.

EXAMPLE 4

The moisture vapor permeability of the adhesive of Example 3 wasincreased by the addition of a poly methyl vinyl ether. (Lutanol M40).

A 50/50 blend on a solids basis was knife-coated on to microporousP.V.C. foil at a dry coating weight of 75 g./sq.m. Dressings made fromthis had a moisture vapor permeability of 780. The dressings performedwell in user trials, although adhesives based on methyl vinyl ethersalone were not expected to possess sufficient water resistance for thispurpose.

EXAMPLE 5

Adhesive composition C (described below) was knife-coated on tomicroporous P.V.C. foil at a dry coating weight of 72 g./sq.m.

This gave dressings having moisture vapor permeability higher than thatgiven by a similar formulation based on ethyl vinyl ethers without thepoly hydroxy propyl acrylate (HPA), e.g., a moisture vapor permeability555 was increased to 667 by this addition of HPA.

EXAMPLE 6

A cast film 0.0025 inch thick and consisting of a copolymer of 80percent by volume EEMA and 20 percent by volume HEMA with its castingpaper still attached was spread with a solvent-based polyvinyl ethylether pressure-sensitive adhesive (adhesive composition A). The amountof adhesive was 16 grams per square meter. The adhesive was then driedin an oven and the coated film mounted on to a release-coated paperprotector. The casting paper was then removed and the laminate made intoa kit of individual nail covers. The film alone had a moisture vaporpermeability of 1,400, the adhesive a moisture vapor permeability of3,000 and the completed nail cover a moisture vapor permeability of 960.

A trial showed that the nail covers performed adequately and did notcause damage to the nail.

EXAMPLE 7

A first aid dressing was made up using a 0.002-inch cast film (copolymerof 20 percent by volume HEMA and 80 percent by volume EEMA) and the filmcoated with 30 grams per sq. meter of a polyvinyl ethyl ether adhesive(adhesive composition A). A protector consisting of a low-releasesilicon-coated parchment (No. E1952 as marketed by Leonard Stace Ltd.)was applied to the adhesive surface of the dressing which had a moisturevapor permeability of 690.

EXAMPLE 8

A surgical drape was made up by coating a 0.002-inch thick cast film (20percent by volume HEMA 80 percent by volume EEMA copolymer with 16 gramsper square meter of a polyvinyl ethyl ether adhesive (adhesivecomposition A). The marginal edges on two opposed parallel sides wereleft unspread. A silicone-release-coated paper was applied to theadhesive as a protector. The moisture vapor permeability of the surgicaldrape (excluding the protector) was 1,080.

EXAMPLE 9

A 1.6 oz. per square yard spun-bonded nonwoven fabric (Reemay type 2415)was laminated to an 0.002-inch thick cast film (copolymer of 20 percentby volume HEMA and 80 percent by volume EEMA). The film side was thencoated with 90 grams per square meter of a polyvinyl ethyl etheradhesive (adhesive coposition A) and a release-coated card was thenapplied to the adhesive surface. The resulting laminate was split intoone-eighth of an inch by 3 inch strips which were then packed in a peelpack to be used as suture strips. The suture strips had a moisture vaporpermeability of 340.

EXAMPLE 10

A cast film 0.0025 of an inch thick and consisting of a copolymer madeby copolymerizing a mixture 50 percent by volume EEMA and 50 percent byvolume MEMA with its casting paper still attached was spread with asolvent-based polyvinyl ethyl ether pressure-sensitive adhesive(adhesive composition A). The amount of adhesive was 16 grams per squaremeter. The adhesive was then dried in an oven and the coated filmmounted on to a release-coated paper protector. The casting paper wasthen removed and the laminate made into a kit of individual nail covers.The nail covers (excluding the protector) had a moisture vaporpermeability of 940.

Nail covers in accordance with this example were given to 20 volunteersand used for 72 hours or more.

Examination of the nails showed that no significant nail damage occurredwhen compared with a conventional nitrocellulose lacquer used as acontrol. The nail covers had an excellent appearance and did not causeany irritation.

EXAMPLE 11

A first aid dressing was made up using a 0.002-inch cast film (of acopolymer obtained by copolymerizing a mixture of 50 percent by volumeMEMA and 50 percent by volume EEMA) and the film coated with 30 gramsper sq. meter of a polyvinyl ethyl ether adhesive (adhesive compositionA). A protector consisting of a low-release silicone-coated parchment(No. E 1952 as marketed by Leonard Stace Ltd.) was applied to theadhesive surface of the dressing.

The dressing (excluding protector) had a moisture vapor permeability of780.

EXAMPLE 12

A surgical drape was made up by coating a 0.002-inch thick cast film (ofa copolymer obtained by copolymerizing a mixture of 50 percent by volumeMEMA 50 percent by volume EEMA) with 16 grams per sq. meter of apolyvinyl ethyl ether adhesive (adhesive composition A). The marginaledges on two opposed parallel sides were left unspread. Asilicone-release-coated paper was applied to the adhesive as aprotector. The drape (excluding protector) had a moisture vaporpermeability of 1080.

EXAMPLE 13

A 1.6 oz. per square yard spun-bonded nonwoven fabric (Reemay type 2415)was laminated to an 0.002-inch thick cast film (of a copolymer obtainedby copolymerizing a mixture of 50 percent by volume MEMA and 50 percentby volume EEMA). The film side was then coated with 90 grams per squaremeter of a polyvinyl ethyl ether adhesive (adhesive composition A) and arelease-coated card was then applied to the adhesive surface. Theresulting laminate was split into one-eighth of an inch by 3 inch stripswhich were then packed in a peel pack to be used as suture strips. Thesuture strips (excluding protector) had a moisture vapor permeability of350.

EXAMPLE 14

Adhesive composition D (see below) was knife-coated onto asilicone-coated release paper, to give a dry coating weight of 60 g.s.m.After drying, a spun-bonded fabric (Reemay 2415) was laminated to theadhesive and the release paper stripped away. Small dressing pads wereplaced on the adhesive, and first aid dressings cut out.

The dressings had a moisture vapor permeability of 1,100, adheredsatisfactorily to human skin, and did not cause skin maceration orirritation.

EXAMPLE 15

Adhesive composition E (see below) was knife-coated onto a release paperto give 40 g.s.m. dry coating weight. The dry adhesive w was transferredby lamination to a nonwoven spun-bonded polyester fabric having anappreciable degree of stretch and recovery (No. 1520 by Bondina Ltd).

This was then cut into strips 3 inches wide by 3 yards long and rolledup with a silicone paper interleaf for use as adhesive compressionbandages. These bandages had a M.C.P. of 110 units.

EXAMPLE 16

Adhesive materials were prepared from a backing material of a polymerobtained by copolymerizing a 50/50 mixture of EEMA/MEMA and adhesivecomposition A (see below). The accompanying drawing shows the moisturevapor permeability of these various films in the form of a graph(log/log scale) in which moisture vapor permeability (along the ordinateor y-axis) is plotted against mass of adhesive (along the abscissa orx-axis) (g./sq. meter for the adhesive alone (line A), the adhesive on0.001-inch (line B); 0.0015-inch (line C) 0.002-inch (line D);0.0025-inch (line E) and 0.0030-inch (line F) backings.

EXAMPLE 17

A self-cross-linking acrylic ester copolymer in ethyl acetate solution(Acronal KR 2156 supplied by BASF) was reverse-roll-coated onto a 1-milthick polyurethane film (Estane 5702 solution cast) to give a drycoating weight of 60 g.s.m.

The polyurethane film, with the wet coating of adhesive solution waspassed through a hot-air-drying tunnel at 75° C. which caused theadhesive to foam up as it dried.

At the reel up, a siliconized paper interleaf was laminated to theadhesive, passing through nip rollers applying sufficient pressure toburst much of the foam (50 p.s.i. on the actuating cylinders of a Dixoncoater model 160, 12 inch wide).

Samples of film/adhesive tested for MVP gave a figure of 820.

Similar film coated with Acronal KR 2156, but not foamed, gave an MVPfigure of 550 units.

EXAMPLE 18

A surgical drape was made up by coating a 0.0032-inch (±0.0002-inch)thick cast film of a copolymer obtained by copolymerizing a mixture of50 percent by volume MEMA and 50 percent by volume EEMA with 50 g./sq.meter of adhesive composition A. The marginal edges on two opposedparallel sides were left unspread. A silicone-release-coated paper wasapplied to the adhesive as a protector. The surgical drape (excludingprotector) had the following properties.

    ______________________________________                                        Moisture vapor permeability                                                                         525 ± 25                                             Tensile strength      2.2 ± 0.3 lb./in                                     Yield point           1.7 ± 0.1 lb./in.                                    Elongation at break   300 ± 40%                                            ______________________________________                                    

EXAMPLE 19

Example 10 was repeated using a 0.0021-inch (±0.0002-inch) film and anadhesive spread of 18 g./sq. meter.

The moisture vapor permeability of the film alone was 1,800 and of thefilm coated with adhesive was 1,050.

EXAMPLE 20

A 0.011-inch microporous plasticized PVC film was given 60 g.s.m.coating of adhesive composition A by transfer from asilicone-release-coated paper. The coated film was made up into smallfirst aid dressings and used in a clinical trial on volunteers forhealing cuts, abrasions and blisters on the fingers. Of the 500dressings used only 3 showed signs of maceration, attributed to liftingand ingress of water. In all other cases the wound healing wassatisfactory over the periods of inspection varying from 5 hours to 3days.

The dressings had a moisture vapor permeability of 600.

It will be appreciated that the materials used in the examples are forillustration only and many other materials could be used, e.g., the50/50 EEMA/MEMA copolymer used in Examples 12 to 15 could be replaced bysay a 70/30 MEMA/EEMA or 60/40 MEMA/EEMA copolymer.

The following are adhesive compositions used in many of the aboveexamples.

ADHESIVE COMPOSITION A

    ______________________________________                                        Bakelite EDBC       50     parts by weight                                    Bakelite EHBM       100    parts by weight                                                               (of solution                                                                  as received)                                       Kelrez ZR142        25     parts by weight                                    Antioxidant (Nonex WSL                                                                            3      parts of weight                                    60-80 petroleum ether                                                                             300    ml.                                                ______________________________________                                    

The Bakelite EDBC and the Bakelite EHBM were mixed together in atwo-blade mixer and the Nonex WSL and Kelrez ZR 142 was added as a 25percent solution in a portion of the petroleum ether. When the mass hadbeen thoroughly mixed it was diluted to working viscosity using the restof the petroleum ether.

This polyvinyl ethyl ether adhesive has an oxygen permeability, whencoated as a 0.0126-inch layer (70-74 g./sq. meter) on a microporousP.V.C. base, of 5,000 cc./sq. meter/24 hours/atms.

ADHESIVE COMPOSITION B

An adhesive composition was prepared by dissolving in 60 to 80 petroleumether solvent, the following ingredients:

    ______________________________________                                        Bakelite EHBM      1     part by weight                                       Bakelite EDBC      1     part by weight                                                                (of solution                                                                  received)                                            Kelrez ZR 142      0.5   parts by weight                                      ______________________________________                                    

ADHESIVE COMPOSITION C

This adhesive was prepared from the following ingredients:

    ______________________________________                                                            Parts by weight                                           ______________________________________                                        Bakelite EDBC         30                                                      Bakelite EHBM         85.2                                                    Kelrez ZR 142         15.35                                                   Poly hydroxy propyl acrylate                                                                        33.35                                                   Ethanol               130                                                     60/80 petroleum ether to                                                                            40% solids.                                             ______________________________________                                    

ADHESIVE COMPOSITION D

An adhesive was made up to the following formulation:

    ______________________________________                                                          parts by weight                                             ______________________________________                                        Acronal 40D         50                                                        Lutonal M40 (aq.)   50                                                        ______________________________________                                    

This adhesive had the following properties

    ______________________________________                                        Williams plasticity K.sub.2.sup.40                                                                      273                                                 Peel adhesion to steel at 60 g.s.m.                                           (T0 B.S.2.110)530 g/cm. width                                                 ______________________________________                                    

Moisture vapor permeability at 60 g.s.m. (on film with water vaporpermeability of 1915); 1075.

ADHESIVE COMPOSITION E

An adhesive was made up to the following formulation:

    ______________________________________                                                          Parts by weight                                             ______________________________________                                        Gantrez M 574       100                                                       Gelva D 260         20                                                        Kelrez ZR 142       25                                                        ______________________________________                                    

The following test results were obtained at 60 g.s.m. coating weight:

    ______________________________________                                        Williams plasticity K.sub.2.sup.40                                                                     120                                                  Moisture permeability                                                         (on film of M.V.P. 1919) 752                                                  ______________________________________                                    

The following are descriptions of some of the materials referred to inthe general description and in the examples.

Bakelite Resin EHBM is a poly (vinyl ethyl ether) high-viscosity resinhaving 25 percent non-volatiles in hexane, a reduced viscosity at 20° C.of 4.0±0.5; a plasticity of 1.6 to 2.0 mm.; a flashpoint <20° F.; aspecific gravity of C. 7,299 and a weight per gallon of 6.07 lbs.

Bakelite Resin EDBC is a poly (vinyl ethyl ether) low-viscosity resinhaving 98 percent nonvolatiles; a reduced viscosity at 20° C. of0.3±0.1; a specific gravity at 20° C. of 0.973 and a weight per gallonof 8.12 lbs.

Kelrez ZR142 is a zinc resinate formed by the interaction of zinc oxideswith the resin acids in partially dimerized Colophony, contains 9.6percent zinc and has a melting point of 160° to 165° C.

Acronal 40 D is an aqueous dispersion of acrylic polymers (50 percentsolids) sold by B.A.S.F.

Lutonal M40 (aq.) is a soft polymer of methyl vinyl ether dissolved inwater (50 percent solids) sold by B.A.S.F.

Gantrez M574 is a solution of polymethyl vinyl ether sold by GeneralAniline and Film Corporation.

Gelva D260 is a solution of copolymers of acrylic alkyl esters sold byGeneral Aniline and Film Corporation.

Gentac is a butadiene/vinyl-pyridine copolymer latex.

NONOX is a phenol condensate.

ESTANE is a linear polyrethane elastomer.

REEMAY is a nonwoven fabric formed from a polyester spun-bondedfilament.

HETEROFIL is a staple fiber of filament comprising a polymeric core andouter layer of a polymer of lower melting point than that of the innerlayer. The polymer is a polyamide in the case of both the core and theouter layer and the core and outer layer may both be derived from thesame monomer but will have different molecular weights in order toproduce the different melting points.

The EEMA used in Examples 8 to 15 contained 2-ethoxy ethyl methacrylatefor the most part together with a very small proportion of acid as animpurity.

The HEMA used in Examples 8 to 11 contained 2-hydroxy ethyl methacrylatefor the most part, together with a small amount of di-ethylene glycolmonomethacrylate, ethylene glycol dimethacrylate and methacrylic acid asimpurities.

The EEMA/HEMA copolymer film of Example 10 has an oxygen permeabilitytransmission rate when measured according to B.S. 2,782; 1,965 method514 A, was found to be 5,000 ml./sq.meter/24 hours/Atms./thou.thickness.

The poly hydroxy propyl acrylate was prepared by polymerizing hydroxypropyl acrylate in ethanol using benzoyl peroxide catalyst to give asolid rubbery polymer soluble in ethanol.

The moisture vapor permeabilities of a number of the continuous backingmaterials used in accordance with the present invention are given below:

    ______________________________________                                                             Moisture vapor permeability                                         Thickness g./sq.m./24 hrs at 40° C.                         Film       (× 0.001")                                                                        & 80% RH)                                                ______________________________________                                        EEMA       4.5        880                                                     EEMA/HEMA  2.5       1400                                                     (80:20)                                                                       EEMA/Methyl                                                                              2.5       1020                                                     Methacrylate                                                                  (80:20)                                                                       MEMA       4.3       1140                                                     MEMA/Methyl                                                                              2.0       1650                                                     Methacrylate                                                                  (90:10)                                                                       MEMA/HEMA  1.5       2460                                                     (90:10)                                                                       MEMA/EEMA  2.1       1800                                                     (50:50)                                                                       MEMA/HEMA  2.7       1650                                                     (70:30)                                                                       ______________________________________                                    

We claim:
 1. A moisture-vapour-permeable pressure-sensitive adhesivematerial for use on .[.animal.]. .Iadd.human .Iaddend.skin .[.andnails,.]. comprising a .Iadd.continuous .Iaddend.backing material.[.,.]..Iadd.which is on unreinforced thermoplastic polyurethane film.Iaddend.and a .Iadd.continuous .Iaddend.pressure sensitive adhesive onat least substantially the whole of the body-adhering portion of atleast one surface of said .Iadd.continuous .Iaddend.backing material,both said .Iadd.continuous .Iaddend.backing material and said.Iadd.continuous .Iaddend.adhesive being .[.moisture-vapour-permeable,and unaffected by water.]. .Iadd.oxygen-permeable, synthetic polymerswhich are moisture vapour permeable, unaffected by water .Iaddend..[.andat least one of said backing material and said adhesive comprising asynthetic polymer and being continuous.]. and .[.nonpermeable.]..Iadd.non-permeable .Iaddend.to liquid water said adhesive materialhaving a moisture vapor permeability of at least .[.300.]..Iadd.500.Iaddend.g/sq. meter/24hours/40° C./80° percent RH. .[.2. Apressure-sensitive adhesive material as claimed in claim 1, which has amoisture vapor permeability of at least 500 g./sq. meter/24 hours at 40°C. and 80 percent RH..]. .[.3. A pressure-sensitive adhesive material asclaimed in claim 1, which is oxygen-permeable..]. .[.4. Apressure-sensitive adhesive material as claimed in claim 1, wherein thebacking material is continuous and the adhesive is not continuous..]. 5.A pressure-sensitive adhesive material as claimed in claim 1, which is.[.in the form of.]. a surgical drape.[., suture strip or sheet,adhesive.]. .Iadd.or wound .Iaddend.dressing.[., bandage, plaster,strapping tape, decorative nail covering, or decorative cosmeticproduct.]..
 6. A moisture-vapour-permeable pressure-sensitive adhesivematerial for use on .[.animal.]. .Iadd.human .Iaddend.skin .[.andnails,.]. comprising a .Iadd.continuous .Iaddend.backing material.Iadd.which is on unreinforced thermoplastic polyurethane film.Iaddend.and a .Iadd.continuous.Iaddend..[.pressure-sensitive.]..Iadd.pressure sensitive.Iaddend.adhesive .Iadd.selected from the group consisting of polyvinylethyl ethers and acrylic ester copolymers containing hydrophilic groups.Iaddend.on at least substantially the whole of the body-adheringportion of at least one surface of said .Iadd.continuous.Iaddend.backing material, both said .Iadd.continuous .Iaddend.backingmaterial and said .Iadd.continuous .Iaddend.adhesive being.[.moisture-vapour-permeable .[.and.]. .Iadd.synthetic polymers whichare .Iaddend.unaffected by water and .[.at least said adhesivecomprising a synthetic polymer and being continuous and nonpermeable.].and .Iadd.are non-permeable .Iaddend.to liquid water, said adhesivematerial having a moisture .[.vapor.]. .Iadd.vapour.Iaddend.permeability of at least .[.300.]. .Iadd.500.Iaddend.g/sq..[.meter.]. .Iadd.meter.Iaddend./24 hours/40° C./80 percent RH. percentRH. .[.7. A pressure-sensitive adhesive as claimed in claim 6 whereinthe adhesive is a polyvinyl ethyl ethers or an acrylic ester copolymercontaining hydrophilic groups..]. .[.8. A pressure-sensitive adhesivematerial as claimed in claim 6 wherein the backing material isnoncontinuous..]. .[.9. A pressure-sensitive adhesive material asclaimed in claim 8 wherein the backing material is a microporous film ofplasticized polyvinyl chloride or nonwoven fabric..]. .[.10. Apressure-sensitive adhesive material as claimed in claim 9, wherein thenonwoven fabric is based on cellulose or synthetic polymer fibers whichmay be crimped and/or laid down in such a manner as to give an elasticfabric..]. .[.11. A pressure-sensitive adhesive material as claimed inclaim 10, wherein the fabric comprises extruded composite syntheticfibers or a spun-bonded polyester fabric..].
 12. Amoisture-vapour-permeable pressure-sensitive adhesive material for useon animal skin and nails.[.,.]. comprising a backing material.Iadd.which is an unreinforced thermoplastic polyurethane film.Iaddend.having a pressure-sensitive adhesive on at least substantiallythe whole of the body-adhering portion of at least one surface of saidbacking material, both said backing material and said adhesive beingmoisture-vapour-permeable and unaffected by water and both said backingmaterial and said adhesive comprising a synthetic polymer and beingcontinuous and nonpermeable.]. .Iadd.non-permeable .Iaddend.to liquidwater, said adhesive material having a moisture vapor permeability of atleast 300 g./sq. meter/24 hours/ 40° C./80 percent RH. .[.13. Apressure-sensitive adhesive material as claimed in claim 12 wherein thebacking material comprises a copolymer obtainable by copolymerizing anhydroxy alkyl acrylate or methacrylate with an alkoxy alkyl acrylate ormethacrylate and optionally with a minor amount of a further monomer..]..[.14. A pressure-sensitive adhesive material as claimed in claim 12,wherein the backing material comprises a homopolymer of ethoxy ethylmethacrylate or methoxy ethyl methacrylate or a copolymer of methylmethacrylate with ethoxy ethyl methacrylate or methoxy ethylmethacrylate..]. .[.15. A pressure-sensitive adhesive material asclaimed in claim 12 wherein the backing material comprises athermoplastic polyurethane film..].
 16. A pressure-sensitive-adhesivematerial as claimed in claim 12, wherein the adhesive .Iadd.is.Iaddend..[.comprises.]. a polyvinyl ethyl ether.
 17. Apressure-sensitive adhesive material as claimed in claim 12 which is.[.in the form of a nail cover,.]. a medical or surgical dressing.[.,.]..Iadd.or .Iaddend.a surgical drape.[., a suture strip, an elasticadhesive bandage or a strapping tape.].. .[.18. A pressure-sensitiveadhesive material as claimed in claim 12, which is in the form of a nailcover and the backing material has a thickness of from 1 to 3 mils..]..[.19. A pressure-sensitive adhesive material as claimed in claim 17which is in the form of a nail cover and in which the adhesive isapplied in an amount of from 5 to 75 grams per square meter..]. .[.20. Apressure-sensitive adhesive material as claimed in claim 12 wherein thebacking material comprises a copolymer obtainable by reacting an alkoxyalkyl acrylate or methacrylate with a different alkoxy alkyl acrylate ormethacrylate, no monomers other than alkoxy alkyl acrylates ormethacrylates or polymers formed therefrom being present in the reactionmixture..]. .[.21. A pressure-sensitive adhesive material as claimed inclaim 20, wherein the backing material comprises a copolymer ofethoxyethyl methacrylate and methoxy ethyl methacrylate..]. .[.22. Apressure-sensitive adhesive material as claimed in claim 21, wherein thebacking material comprises a 50/50, 60/40 or 70/30 copolymer ofMEMA/EEMA..]. .[.23. A pressure-sensitive adhesive material as claimedin claim 20 wherein the adhesive comprises a polyvinyl ethyl ether..]..[.24. A pressure-sensitive adhesive material as claimed in claim 20which is in the form of a suture strip and which is wholly or partiallyreinforced with woven or nonwoven fabrics..]. .[.25. Apressure-sensitive adhesive material as claimed in claim 13 wherein saidhydroxy alkyl acrylate or said methoacrylate comprises hydroxy ethylmethacrylate, hydroxy propyl acrylate, or hydroxy propyl methacrylate,and wherein said alkoxy alkyl acrylate or methacrylate comprises ethoxyethyl methacrylate or methoxy ethyl methacrylate..]. .[.26. Apressure-sensitive adhesive material as claimed in claim 17 in which thebacking material is reinforced by a nonwoven material..]. .Iadd.27. Apressure-sensitive adhesive material as claimed in claim 1 which is asurgical drape..Iaddend. .Iadd.28. A pressure-sensitive adhesivematerial as claimed in claim 1 which is an adhesive dressing..Iaddend..Iadd.29. A pressure-sensitive adhesive material as claimed in claim 12which is a medical dressing..Iaddend. .Iadd.30. A pressure-sensitiveadhesive material as claimed in claim 12 which is a surgicaldressing..Iaddend. .Iadd.31. A pressure-sensitive adhesive material asclaimed in claim 12 which is a surgical drape..Iaddend. .Iadd.32. Apressure-sensitive adhesive as claimed in claim 1 wherein the adhesiveis a polyvinyl ethyl ether..Iaddend. .Iadd.33. A pressure-sensitiveadhesive as claimed in claim 1 wherein the adhesive is an acrylic estercopolymer containing hydrophilic groups..Iaddend. .Iadd.34. A pressuresensitive adhesive material as claimed in claim 16 which is a wounddressing or surgical drape..Iaddend. .Iadd.35. A pressure sensitiveadhesive material as claimed in claim 12 wherein the adhesive is anacrylic polymer..Iaddend. .Iadd.36. A pressure sensitive adhesivematerial as claimed in claim 12 wherein the adhesive is an acrylic estercopolymer containing hydrophilic groups..Iaddend.